The invention relates to improvements in apparatus for manipulating sheet-like or panel-like objects, especially X-ray films. More particularly, the invention relates to improvements in apparatus for orienting sheet-like or panel-like objects (hereinafter referred to as films or X-ray films) in magazines wherein the films are stacked on top of or next to each other so that the oriented films are ready for removal from the magazine, e.g., by a withdrawing unit which is positioned in such a way that it can properly engage and withdraw only a fully oriented film.
It is customary to confine X-ray films in tightly sealed magazines which are provided with sealable openings to permit evacuation (e.g., by suction) of properly oriented films. Proper orientation of a film prior to withdrawal from the magazine is desirable and necessary if the magazine contains large, medium-sized and small films, i.e., if the films which are confined in the magazine merely overlie but do not necessarily register with each other.
It is already known to provide apparatus which are capable of orienting large, medium-sized and/or small films in a magazine prior to evacuation of films. The orientation normally involves a shifting of the film to be evacuated against a stop so that the thus shifted film is within the range of the film evacuating or withdrawing unit. Reference may be had to commonly owned German Pat. No. 31 22 585 to Muller et al. and to corresponding U.S. Pat. No. 4,566,682 which show (in FIGS. 3 to 5) a single wheel movable into frictional engagement with the exposed side of the outermost film of a stack of films in the magazine in order to shift the outermost film into contact with an internal stop of the magazine. The internal stop is a surface which extends at right angles to the planes of films in the magazine. The oriented film is thereupon engaged by a plurality of suction cups which extract it from the magazine.
A drawback of the patented apparatus is that it can properly orient only those films which are confined in a relatively small magazine. Thus the maximum length of a film must exceed half the length of the magazine; otherwise, the single wheel is likely to miss a relatively small film so that such film is not advanced into engagement with the stop and cannot be withdrawn from the magazine. Moreover, the single wheel of the patented apparatus cannot invariably ensure optimum orientation of a shifted film with reference to the stop in the magazine. For example, it can happen that only one corner of the shifted film contacts the stop so that, upon extraction from the magazine, the orientation of the film is far from satisfactory.